On Mon, Nov 07, 2016 at 08:09:20PM +0000, Paul Burton wrote:
> Commit 70121f7f3725 ("i2c: octeon: thunderx: Limit register access
> retries") attempted to replace potentially infinite loops with ones
> which will time out using readq_poll_timeout, but in doing so it
> inverted the condition for exiting this loop.
>
> Tested on a Rhino Labs UTM-8 with Octeon CN7130.
>
> Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
> Cc: Jan Glauber <jglauber@xxxxxxxxxx>
> Cc: David Daney <david.daney@xxxxxxxxxx>
> Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
> Cc: linux-i2c@xxxxxxxxxxxxxxx
>
> ---
Acked-by: Jan Glauber <jglauber@xxxxxxxxxx>
Thanks for spotting this. I think this should go into stable too for
4.8, so adding Cc: stable@xxxxxxxxxxxxxxx.
> drivers/i2c/busses/i2c-octeon-core.h | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-octeon-core.h b/drivers/i2c/busses/i2c-octeon-core.h
> index 1db7c83..d980406 100644
> --- a/drivers/i2c/busses/i2c-octeon-core.h
> +++ b/drivers/i2c/busses/i2c-octeon-core.h
> @@ -146,8 +146,9 @@ static inline void octeon_i2c_reg_write(struct octeon_i2c *i2c, u64 eop_reg, u8
>
> __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI(i2c));
>
> - readq_poll_timeout(i2c->twsi_base + SW_TWSI(i2c), tmp, tmp & SW_TWSI_V,
> - I2C_OCTEON_EVENT_WAIT, i2c->adap.timeout);
> + readq_poll_timeout(i2c->twsi_base + SW_TWSI(i2c), tmp,
> + !(tmp & SW_TWSI_V), I2C_OCTEON_EVENT_WAIT,
> + i2c->adap.timeout);
> }
>
> #define octeon_i2c_ctl_write(i2c, val) \
> @@ -173,7 +174,7 @@ static inline int octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg,
> __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI(i2c));
>
> ret = readq_poll_timeout(i2c->twsi_base + SW_TWSI(i2c), tmp,
> - tmp & SW_TWSI_V, I2C_OCTEON_EVENT_WAIT,
> + !(tmp & SW_TWSI_V), I2C_OCTEON_EVENT_WAIT,
> i2c->adap.timeout);
> if (error)
> *error = ret;
> --
> 2.10.2
